Abstract
The anterior cruciate ligament (ACL) plays the primary role in resisting anterior tibial translation. ACL rupture inevitably causes alterations in knee kinematics and long-term functional impairment. The purpose of this study was to evaluate a new surgical technique, subosseous screw-suture anchor surgery (SSSAS), for ACL repair of the knee from a biomechanical point of view. Twelve porcine knees were tested with the ACL intact, cut, and repaired (using traditional Pull-Out method or the SSSAS method) on a mechanical testing apparatus. Tibial translation at four knee flexion angles (0°, 30°, 60°, 90°) under three tibial rotation loads (5 N-m, 0, -5 N-m) was measured to determine knee stability. A laxity recovery ratio was defined to account for individual variations and estimate the repair level. Our findings indicate both Pull-Out and SSSAS techniques significantly decreased AP laxity of the knee joint. In addition, the differences between the intact and repaired knees in the Pull-Out group were significant in all three tibial rotation positions. In the SSSAS group, they were significant at 0° and 90° knee flexion for both neutral and internal rotation positions and at 0°, 30°, and 90° knee flexion in the external rotation position. Concerning the laxity recovery ratio, the SSSAS group had higher laxity recovery ratio than the Pull-Out group. In other words, the fixation by directly fixating the ACL on the femoral interchodylar area instead of the fixation through femoral tunnel could give better outcome in terms of knee stability.
